Berlin 2018 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 50: HL Poster IV
HL 50.1: Poster
Thursday, March 15, 2018, 19:00–21:00, Poster B
Geometry-induced effect on magnetoresistance in open superconductor microtubes — Roman Rezaev1,2, Ekaterina Smirnova1, Evgeniy Posenitskiy1, Evgeniy Levchenko1, and •Vladimir Fomin3 — 1Tomsk Polytechnic University, Tomsk, 634050, Russia — 2Moscow Engineering Physics Institute, Moscow, 115409, Russia — 3Insitute for Integrative Nanosciences, IFW Dresden, Dresden, D-01069, Germany
Superconductor order parameter is analyzed numerically in an open superconductor Nb microtube in an applied magnetic field orthogonal to the tube axis in the presence of a transport current flowing from one to the other bank of the cut. An open microtube manifests significantly different behavior of magnetoresistance due to the vortex motion as compared to the planar membrane of the same dimensions. The magnetoresistance in an open tube as a function of the magnetic field reveals an expressed geometry-induced peak. A three-fold increase of the magnetoresistance in its peak value at 7.5 mT is revealed numerically in an ultrathin Nb tube of radius 500 nm and length 5 μm. This non-monotonic behavior is presumably due to the occurrence of a phase slip line in the area with small absolute values of the normal-to-the-surface magnetic field component, when the quasi-stationary pattern of vortices changes from single to double chains in each half-turn. The effect is promising for design of novel superconductor switching based detectors. The work was partially supported by the Federal Targeted Program of the Russian Federation (agreement no. 14.578.21.0198) and by the COST Action MP1201 Nanoscale Superconductivity.